Febrile seizures: How to determine underlying contributors

The Case

You are in the middle of a busy pediatric emergency department when you receive a call from an ambulance a few minutes away. They are transporting a 12-month-old boy who apparently had a seizure. He is no longer seizing and is reportedly stable.

The patient arrives and the nurses collect his vital signs. He is a young boy who is alert and awake, and sitting in his mom's arms. He appears somewhat ill but not toxic. He cries during the blood pressure measurement, but quiets afterwards. Confident that the boy is stable, you rush off to discharge a few patients.

The boy has been sick for the last two days. He first developed a runny nose and an occasional cough. Today, they report that he developed a fever and has been fussy. While his grandmother was holding him, she noticed he felt warm. When he started shaking all over, the family called 911.

You inquire more about the shaking episode, and find out that his arms and legs started shaking together, and his eyes rolled back in his head. They are unsure of the duration of the episode but think it was less than 5 minutes. He had stopped shaking by the time the ambulance arrived. They do not recall any changes in his color and don't think he stopped breathing. They do not have a thermometer so don't know know how high his fever was.

This is his first episode of shaking. There is no family history of seizures or other neurological problems. He was born at 36 weeks by cesarean delivery, but Mom cannot remember why. He did have a twin sister who had intrauterine demise 2 months prior to delivery. His birth weight was 4 pounds and 2 ounces, and he spent some time in the NICU feeding and growing.

He received his 2-month immunizations, but has not had any since that time. His family had made multiple moves in the last year and has yet to establish primary care. He has been generally well, with no hospitalization or surgeries, developing normally and not on any medications. He lives with his mother, grandmother, aunt, and 3 cousins in an apartment. His cousins have had their immunizations. Two of his cousins are sick with a cold at this time.

As you are in the room, the child starts to seize again. This time he is lying on the bed when he starts having a generalized tonic-clonic seizure. The seizure continues for more than 5 minutes, but he has no signs of respiratory distress. He requires 2 doses of lorazepam to stop the seizure activity.

Given his second seizure, you decide to obtain some labs. His white blood cell (WBC) count is unremarkable at 6,800/mm³ , with 62% neutrophils and no bands. His urinalysis is normal with 0 to 2 WBC/hpf. You also do a lumbar puncture because of his young age, despite his lack of meningeal signs. His cerebrospinal fluid (CSF) is clear with no WBCs and 1 red blood cell/mcgL, normal protein and glucose, and no organisms seen on Gram stain. You are reassured by his normal lab values. You give him a dose of ceftriaxone to treat his ears and also to treat empirically for potential invasive bacterial infection while his cultures are pending. With these unremarkable lab values and a clear source of fever, you debate the need for hospitalization. But, it is late and he is somewhat sleepy from the lorazepam, so you decide to admit him for observation.